The proposed work is concerned with the evaluation of standard methods and the development of new methods to analyze multichannel EEG data base on the integration of physics, engineering, and computer developments with established methods in EEG. A principal objective is to improve the spatial resolution of EEG so that scalp recordings more accurately represent the activity of underlying sources. Another goal is that of the development of methods to quantify spatial patterns of EEG associated with various clinical and cognitive states. The spatial patterns may be potential amplitudes, Laplacian (current source density) estimates, correlation, or coherency patterns. Unique features of this approach include experimental and theoretical estimates of local skull resistance, a comprehensive study if ictal and interictal phenomena in epilepsy patients, analytic and finite element models of the human head, simultaneous recordings of scalp and cortical EEG in cats (64 channels), application of various splines to estimate surface Laplacians in EEG and evoked potentials, and application of spatial deconvolution methods to multichannel scalp data. The proposed methods are applicable to distributed and time-varying sources. Thus, this work can be expected to be directly applicable to a wide variety of future EEG and evoked potentials studies carried out at numerous locations.